Histogenesis of salivary gland neoplasms.

In an attempt to explain the histogenesis of salivary gland tumors, a bicellular theory of origin has been presented. This theory is supported by indirect evidence from light and electron microscopy. Two cells, the excretory duct reserve cell and the intercalated duct reserve cell, are presented as the hypothetical cells of origin for salivary gland neoplasms. It is argued that the excretory duct reserve cell gives rise to squamous cell carcinomas and mucoepidermoid carcinomas, and that the intercalated duct reserve cell gives rise to all others. It It is also shown that myoepithelial cells are responsible in part for the wide histologic variation of these neoplasms.